Annual Report 2005 - Westmead Millennium Institute

Ludwig Engel Centre forRespiratory ResearchSleep disordered breathingThe Ludwig Engel Centre has a particular emphasis on sleepdisordered breathing with an international reputation for researchingthe mechanisms underlying the obstructive sleep apnoea syndrome(OSAS). In this disorder, patients experience repetitive episodes ofthroat blockage during sleep leading to complete cessation ofbreathing for short periods of time. Researchers are working tounderstand the processes associated with the occurrence ofobstructed breathing during sleep in order to improve the treatmentsavailable for this important disorder. Current research programsinclude investigations into the physiology of the upper airway andthe cardiovascular complications of OSAS. New research areas for2006 will allow us identify intermediate phenotypes in obstructivesleep apnoea patients and begin to establish the genetic basis forsleep disordered breathing.Work will soon begin on development of a biomechanicalcomputational model of the hydrostatic mechanics of the tissuespace surrounding the upper airway and its influence on upperairway patency. The role of surface tension of the upper airway liningliquid in the control of upper airway patency during sleep isan ongoing area of research interest, as is the effects of snoring onblood pressure control and stroke.Asthma and chronic obstructivepulmonary diseaseAsthma now affects the lives of over 2 million Australian children andadults. Despite decades of research into the causes and treatmentof asthma, the prevalence of asthma in the population continues torise. A major research interest of this research group is the influenceof mouth versus nose breathing on the occurrence of asthmaticsymptoms. The nose warms, humidifies and filters inspired air,whereas mouth breathing exposes the lungs to unheated, dry,unfiltered air which may contribute to the occurrence or worseningof an attack. Research in this lab recognised that asthmatic subjectshave altered perception of nasal obstruction, leading them to switchto mouth breathing more readily than healthy individuals, and thatthis switch may contribute to the development of an asthmaepisode. Currently, researchers are investigating whether nasalbreathing can help to resolve an episode of asthma. New researchinto chronic obstructive pulmonary disease will examine the value ofaerobic exercise training to the overall benefits of short pulmonaryrehabilitation programmes.Cystic fibrosisCystic fibrosis (CF) is the most common lethal inherited diseaseaffecting Australians. In CF, altered salt transport across the liningof the airways leads to drying of the airway surface, impeding theprocesses that remove mucus from the lungs. Mucus retentionmakes the lungs very susceptible to repeated bacterial infections.Researchers in this group are currently investigatingelectrophysiological abnormalities in CF and determining theinteraction between airway surface divalent ions and the underlyinggenetic defect so that potential new treatments can be developed.